For many years, access control systems have been used in connection with passive RFID transponders (Radio Frequency Identifier). These access control systems included RFID readers for reading in a wireless fashion access rights or at least user identifiers from RFID transponders to control access to an access controlled area, such as a building or a room, or to access controlled objects, such as goods in a vending machine, etc. With the arrival of mobile radio phones (cellular phones) that included active RFID-based communication interfaces, so called NFC interfaces (Near Field Communication), it became possible to use such mobile phones as carrier of access rights rather than passive RFID transponders in form of RFID cards, dongles, or the like. With an NFC interface, it is possible to tie access control to the physical presence of the mobile phone in an area that is near a corresponding NFC interface of an access control device, e.g. attached to or close to a door or a gate. In other words, the short communication range of NFC interfaces requires that a user's mobile phone does not have to great a distance from the door or gate that is to be accessed, making it unlikely that an unauthorized person gets given access erroneously on the basis of access rights stored on the rightful user's mobile phone, as long as the mobile phone is in the possession of the rightful user. However, not all types and brands of mobile phones are equipped with an NFC interface or other RFID-based communication capabilities. Nevertheless, in addition to the mobile radio communication modules used for accessing cellular telephone networks such as GSM (Global System for Mobile Communication) or UMTS (Universal Mobile Telephone System), some types and brands of mobile phones include other radio-based communication modules for establishing local or direct wireless communication links. For example, such radio-based communication modules include WLAN (Wireless Local Area Network) and Bluetooth communication interfaces which have a much larger communication range than NFC interfaces, e.g. ten to a hundred meters. Although such other radio-based communication modules could be used for exchanging access rights with an access control device, there is a risk that an unauthorized user could get erroneous access, only because the rightful user or at least his mobile phone is located within this extended communication range of the access control device.
FR 2981823 describes a method for authenticating identification device with respect to an actuator device integrated in car for carrying out car a start-up operation. In an authentication session, the identification device us authenticated by exchanging authentication data between the identification device and the actuator device. During an authentication session, a first part of the exchanging authentication data is communicated using Bluetooth, while a second part of the authentication data is exchanged through magnetic induction. In the actuator the two parts of authentication data are aggregated.
U.S. 2012/154115 describes a method for controlling access in a location tracking system. When a mobile tag enters a room, it carries out location update procedures and becomes linked to a node of the location tracking system and updates its location in the room. In response to the location update, a location tracking apparatus of the location tracking system transmits an activation signal to an access control apparatus in the room to initiate establishment of a communication connection with the mobile tag so as to negotiate about access rights of the mobile tag. In an embodiment, the access control apparatus may be provided with a proximity sensor which, subsequently to negotiating the access rights, detects the close proximity of the mobile tag, before the access control apparatus actually grants or denies access.
U.S. 2014/049361 describes an electronic system which includes a mobile device that communicates with a reader device associated with an electronic lock. The mobile device and the reader device communicate with each other, e.g. via Bluetooth, and exchange credentials, secure data, and location information. In an embodiment, the electronic lock may also include a close proximity range capability which automatically unlocks the electronic lock when a mobile device with appropriate credentials is within the close proximity range.